The effectiveness of mindfulness-based interventions for ruminative thinking: A systematic review and meta-analysis of randomized controlled trials

Objective: To systematically evaluate the effectiveness of mindfulness-based interventions for ruminative thinking. Methods: Cochrane Library, Web of Science, Embase, EBSCO, PubMed and Science Direct databases were searched to include randomized controlled trials of mindfulness-based interventions for rumination that met the criteria. The Rumination scale was used as the primary outcome indicator, and the secondary outcome indicator included the Mindfulness scale. An evaluation of bias risk was conducted to identify possible sources of bias based on methodological and clinical factors. Stata 16.0 software was used to perform meta-analysis, subgroup analysis, sensitivity analysis, meta-regression analysis and publication bias detection of the extracted data. Results: A total of 61 studies with 4229 patients were included. Meta-analysis results revealed a significant intervention effect on ruminative thinking (SMD = -0.534, 95 % CI = [-0.675, -0.394], z = -7.449, P < 0.001). However, there was no significant difference between mindfulness-based interventions and CBT (SMD = 0.009, 95%CI = [-0.239, 0.258], z = 0.073, P = 0.941). Meta-analysis showed that mindfulness-based interventions significantly enhanced the level of mindfulness (SMD = 0.495, 95 % CI = [0.343, 0.647], z = 6.388, P < 0.001), while it was not significant compared to CBT (SMD = 0.158, 95%CI = [-0.087, 0.403], z = 1.266, P = 0.205). The two subgroups with >65 % (SMD = -0.534, 95%CI = [-0.681, -0.386], z = -7.081, P < 0.001) and 80 % (SMD = 0.462, 95%CI = [-0.590, -0.334], z = -7.071, P < 0.001) of females showed significant improvement in ruminative thinking. There were significant intervention effects for depression, students, cancer, healthy adults, and clinical patients. Significant intervention effects were demonstrated for various participant ages and intervention periods. Conclusion: This study confirmed the feasibility of mindfulness-based interventions in improving ruminative thinking and enhancing the level of mindfulness. However, the effectiveness of mindfulness-based interventions was not significant compared to CBT. The two subgroups with a higher proportion of females showed a more significant improvement in ruminative thinking, whereas there were no significant differences in participant characteristics, age, and the duration of intervention.